Lock



Qfit. 16, 1934. G LARSON ET AL 1,9721%9 LOCK Filed Dec. 4, 1935 Patented Oct. 16 1934 Ivar G. Larson and William Fetzer, Chicago, Ill.

Application December 4, 1933, Serial No. 700,846

Claims.

This invention relates to improvements in looks and it consists of the matters hereinafter described and more particularly pointed out in the appended claims.

One object of theinvention is to provide a lock of the kind having a novel form of key slot that is madeon a curve in'the direction of its length so that it will accept only the key made therefor, and furthermore, will cause the end of a picking tool inserted thereinto to move in such a manner thatthe same cannot be made to properly raise the tumbler pins.

Another object of the invention is to provide a cylinder or pin tumbler lock which though -simple in construction, is practically unpickable and is so protected against drilling that the cylinder cannot be removed from the lock casing in this manner.

Still anotherobject of the invention is to provide a novel means of securing the lock casing in a door or other support and which includes an anchoring pin for the casing which is initially moved into anchoring position by a movement of the cylinder in the casing.

The'above mentioned objects of the invention,

as Well as others, together with the many advantages thereof, will more'fully appear as we proceed with our specification.

In the drawing:

Fig. 1 is a longitudinal vertical sectional view through the improved lock and shows the same with the associated key in place therein to unlock the lock.

.Fig. 2 is a view similar to Fig. 1 with the key "'removed to lock the lock.

'Fig. 31s a transverse vertical sectional view through the look as taken'on the line 3-3 of Fig. l.

Fig; 4. is a view in side elevation of the key associatedwith the lock.

Referring now in detail to that embodiment of" the invention, illustrated in the accompanying drawing:

., lindicates as a whole the tubular lock "casing ""provided at the front end with a radial facing flange 2. Tothe rear of said flange, said casing is externally threaded as at 3 whereby the-casing may be. threaded into a suitable opening in a door or'other support 4. The casing is provided "witha rear end bore portion 5 and a front end bore portion, 5a of enlarged diameter, thus torming'a radial shoulder 6 at the meetings ends of said boreportions.

,--. In the topside of the casing is provided a plurality'of longitudinally spaced recesses leach closed at its outer end by a suitable plug 8 and each opening at its inner end into the bore portions 5 and 5m respectively. Each recess is adapted to receive a tumbler 9, a spring 10 being located in each recess between the plug and tumbler therein to normally urge the tumbler inwardly.

Within the bore of the casing, as provided by the portions 5 and 5a, is journalled a cylinder 11. This cylinder is provided at a point between its ends with a radial shoulder 12 that is opposed to and is spaced forward of the'shoulder 6 to there leave an annular space in which is located a hardened steel ring 13. This ring is so disposed that if it should be attempted to drill the lock along the line of the bore portion 5a, the drill can only proceed so far as the ring which will act to deflect the drill. Thus the drill will either bind or break off.

On the rear end of the cylinder is secured a plate 14 that overlaps said end of the casing. With this plate and the shoulder structure mentioned, the cylinder, cannot be removed from the casing. Said plate 14, of course, is so formed as to be operatively connected to the mechanism it is desired to look so that when the cylinder is turned after insertion of a suitable key, the plate turns therewith to either lock or unlock said mechanism.

The cylinder 11 is provided with a key slotl5 which is preferably corrugated transversely to provide laterally oliset ribs and grooves 16 and 17 respectively. Longitudinally, these ribs and grooves of the key slot are made on substantially parallel curves as best shown in Fig. 2. Said ribs and grooves open at their front ends through the front end of the cylinder and open at their rear ends through the top side of the cylinder. In'the front end of the cylinder is formed a guide recess 18 by which the key later to be described is guided for easy entrance or insertion into the key slot.

In the top side of the cylinder is provided a plurality of openings 19 which when the cylinder is in one position, register with the openings 7, in the casing. The openings 19 which communicats at their inner ends with the key slot, each contains a tumbler pin 20. In the rear or inner end of the cylinder, at the top thereof, is formed an opening 21 which communicates not only with the key slot but also with an opening 22 in the plate 14 whereby such dust or foreign particles as enters the slot, may be released therefrom. At the bottom of said end is formed a recess 23 in which a spring pressed lever 24 is pivoted at a point between its ends. The front arm 25 .of 0

said lever extends into the bottom part of the key slot while the rear arm 26 of said lever is bent downwardly to line up with an opening 27 in the rear end of the bottom side of the casing. Suitably confined in said opening is a springpressed plunger 28, the top end of which is normally engaged by the rear arm 26 of the lever just mentioned. In the recess 23 is provided a spring 29 that normally acts to swing the rear arm of the lever downwardly and the front arm of said lever upwardly. In this manner, the rear arm acts to hold the plunger 28 depressed so that it cannot pass the line of the bore part 5a in which position it would lock the cylinder and casing together. When the spring 29 so holds the rear arm depressed, the front arm is caused to be raised so as to extend into the bottom groove of the key slot.

To look the casing l in the support 4, such as a door or the like, we provide the following:

In the bottom part of the casing, near its front end is an opening 30 with which is associated a recess 31 disposed at an angle thereto and communicating with the top end thereof.

,The opening 30 has associated therewith, an anchoring pin 32 with a conical top end and in the angular recess is a spring-pressed pin 33. In the bottom side of the cylinder is provided a camlike recess 34 which is deeper at the end 35 than .it is at its other end which is best shown in Fig. 3. In the bottom side of the opening in the support 4 which receives the lock casing, is provided a recess 36 which will register" with the opening 39 in the lock casing when the casing ;.is positioned in said opening in said support.

In making the assembly, the pin is inserted in the opening 30 in the casing. The cylinder is then turned in said casing so that the deeper end of the cam groove registers with the opening 30,

when the top end of the pin 32 can extend into "said deeper end. By turning the lock cylinder in the casing, the cam surface of the groove 34 of the'cylinder, will cause the pin 32 to be depressed. This will cause the bottom end of the pin' to enter the recess 36" in the support, when the spring pressed pin 33 will so engage the top end of the pin 32 as to hold it in its casing locking position. Thus it is impossible to reach the pin should an attempt be made to remove the .entire lock assembly from the support.

In Fig. l, we have illustrated, a key for use in connection with the look. This key includes a shank 37 and head 38. The shank which is thereinto. It will be noted that that end of the key opposite the head terminates substantially .as a point whereby when the same is engaged in the cylinder recess 18, it is quickly and easily guided into the key slot.

.When the key is withdrawn from the lock, the spring-pressed tumblers and pins are urged downwardly so that the tumblers project a part 'way into the cylinder andtherefore the cylinder cannot be turned and the lock is in its locked condition. Should it be attempted to pickthe lock with a picking tool or wire, it is of course I apparent that such a tool or wire would have to be inserted into one of the grooves of the key slot. Such a wire or tool would have to be quite slender for such insertion. Because of the longitudinal curvature of the slot, the tool or wire not be engaged with the tumbler pins with enough leverage or purchase to lift them. It is apparent that to lift the tumbler pins, the lifting pressure or force must be imposed thereon in the direction of the axis thereof and with the key slot curved as described, the tool or wire cannot so be presented to the tumbler pins but will merely slip oh? the ends thereof. Should the tool or wire be inserted into thebottom of the key slotQthiswill depress the arm 25and raise the arm 26 so that the spring pressed plunger 28 operates to further lock the cylinder to the casing at this point.

' When the key is inserted in the slot, the key bits 39 will engage with the tumbler pins and lift them the proper distance. The notch 40 in the key at this time will register with the lever arm 25 so that the same remains ineffective to lock the cylinder to the casing at this point. With the key inserted and with the tumbler pins raised the desired distance, the bottom ends of the tumblers line up with the bore parts 5 and 5a so that the cylinder may now be turned by turning the key.

With the parts having the forms mentioned and being arranged as described, it is practically impossible to so engage the tumbler pins with a toolor wire as to manipulate them so as to open the lock.

Whil'e'in describing the invention, we have referred in'detail to the form, arrangement and construction of the various parts of the lock, the same is to be considered only in its illustrative sense so that we do not wish to be limited thereto except as may be specifically set forth in the appended claims.

We claim as our invention:

1. A look embodying therein a casing, a cylinder journalled therein and tumbler members associated with said casing and cylinder, said cylinder having a key slot therein which is curved longitudinally in the plane of its width to receive a complementary shaped tumbler member. actuating key.

2. A lock embodying therein a casing, a cylinm der journalled therein" and tumbler members associated with said casing and cylinder, said cylinder having a key slot therein which is curved longitudinally at leastin part in the plane of its width, to receive a complementary shaped tumbler member actuating key.

3. A look embodying therein a casing, a cylinder journalled therein and tumbler members associated with said casing and cylinder, said cylinder having a key'slot therein which is corrugated m transversely and is curved longitudinally in the plane of its width to receive a complementary shaped, tumbler member'actuating key.

4. A look embodying therein a casing, a cylinder joumalled therein and tumbler members associated with said casing and cylinder, said cylinderhaving a key slot therein which is corrugated transversely and is curved longitudinally at least in part inthe plane of its width, to receive a complementary shaped tumbler'member actuating key.

5. In combination with a support, a lock'casing disposed therein, a cylinder turnable in said casing, key operable means for locking said cylinder against turning in said casing, means arranged 145 in said casing for engaging said support to lock the same thereto, said means being movableinto said support engaging means by an initial turn ing movement of the cylinder and other means would have to follow the same so that it could carried by the casing to lock said support engaging means in position independent of the cylinder.

6. In combination with a support, a lock casing disposed therein, a cylinder turnable in said casing, key operable means for locking the cylinder against turning in said casing, means arranged in said casing for engaging said support to lock the same thereto, said means being movable into said support engaging means by an initial turning movement of the cylinder, and spring pressed means also carried by the casing and arranged at an angle to said support engaging means to lock the same in said support engaging position after the same has been moved into said position by the initial turning of the cylinder in the casing.

'7. A lock embodying therein a member formed with a key receiving slot having an outer entrance end and an inner end, said slot being curved longitudinally in the plane of its width so that said inner end is ofiset into a plane difierent from that of said outer end.

8. A look having a part formed with a slot that is curved longitudinally in the plane of its width and has an outer entrance end and an inner end that opens through the top side of said part to receive a complementary shaped key.

9. A look having a part formed With a key receiving slot that is curved longitudinally in the plane of its width and is provided in the sides thereof with at least a groove and a rib that follow the curvature of the slot.

10. A look having a part formed with a key receiving slot which is curved longitudinally in the plane of its width and is formed with longitudinally extending grooves in its sides that terminate at one end at difierent points along the length of the slot.

IVAR G. LARSON. WILLIAM FETZER.

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